Claude Sonnet 4.5 vs Claude Sonnet 4.6

Claude Sonnet 4.5 (2025) and Claude Sonnet 4.6 (2026) are frontier-tier reasoning models from Anthropic. Claude Sonnet 4.5 ships a 200k-token context window, while Claude Sonnet 4.6 ships a 1m-token context window. On MMLU PRO, Claude Sonnet 4.6 leads by 1.3 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Claude Sonnet 4.6 fits 5x more tokens; pick it for long-context work and Claude Sonnet 4.5 for tighter calls.

Decision scorecard

Local evidence first
SignalClaude Sonnet 4.5Claude Sonnet 4.6
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window200k1m
Cheapest output$15/1M tokens$15/1M tokens
Provider routes8 tracked6 tracked
Shared benchmarks5 sharedMMLU PRO leader

Decision tradeoffs

Choose Claude Sonnet 4.5 when...
  • Claude Sonnet 4.5 has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Choose Claude Sonnet 4.6 when...
  • Claude Sonnet 4.6 holds a shared-benchmark lead on MMLU PRO, ahead by 1.3 points.
  • Claude Sonnet 4.6 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Claude Sonnet 4.6 uniquely exposes Code execution, Computer use, and Parallel agents in local model data.
  • Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Same estimate Tie

Claude Sonnet 4.5

$6,150

Cheapest tracked route/tier: Microsoft Foundry

Claude Sonnet 4.6

$6,150

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $0.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Sonnet 4.5 -> Claude Sonnet 4.6
  • Provider overlap exists on OpenRouter, Anthropic, and AWS Bedrock; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
  • Claude Sonnet 4.6 adds Code execution, Computer use, and Parallel agents in local capability data.
Claude Sonnet 4.6 -> Claude Sonnet 4.5
  • Provider overlap exists on Microsoft Foundry, Anthropic, and GCP Vertex AI; start route-level A/B tests there.
  • Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
  • Check replacement coverage for Code execution, Computer use, and Parallel agents before moving production traffic.

Specs

Specification
Released2025-09-292026-02-17
Context window200k1m
Parameters——
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-122025-08

Pricing and availability

Pricing attributeClaude Sonnet 4.5Claude Sonnet 4.6
Input price
0-200,001t
$3/1M tokens
200,001t+
$6/1M tokens
$3/1M tokens
Output price
0-200,001t
$15/1M tokens
200,001t+
$22.50/1M tokens
$15/1M tokens
Providers
Microsoft FoundryAnthropicSnowflake CortexGCP Vertex AIAWS BedrockReplicate API
OpenRouterAnthropicAWS BedrockGCP Vertex AIMicrosoft FoundryVercel AI Gateway

Capabilities

CapabilityClaude Sonnet 4.5Claude Sonnet 4.6
VisionYesYes
MultimodalYesYes
ReasoningYesYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoYes
Parallel agentsNoYes

Benchmarks

BenchmarkClaude Sonnet 4.5Claude Sonnet 4.6
MMLU PRO86.087.3
SWE-bench Verified77.279.6
Google-Proof Q&A83.489.9
Massive Multi-discipline Multimodal Understanding77.883.6
MMMU Pro68.975.6

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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.